A made-up wildfire spreading over the real terrain of the Sangre de Cristo range above Santa Fe, NM. Drag to pan, scroll to zoom, right-drag (or Ctrl-drag) to tilt.
Press Start. Fire spreads cell-to-cell — faster uphill and downwind — and each cell is shaded by how long ago it burned, so the burn scar reads as a progression map. The bright rim is the active fire front. Click the map to move the ignition point.
Shift-drag a rectangle (the dashed box) to move the whole model region — pan anywhere first, so you can burn a ridge in another state.
See README.md for the spread model and the GeoJSON it produces.